The current practice, onboard Navy ships, is to use Golar-type incinerators to dispose of waste. These incinerators are refractory lined vessels into which un-shredded or shredded waste is fed through a feed port. Additional heat is typically supplemented by fuel oil burners. These incinerators typically do not have a secondary combustion chamber or any type of gas cleaning system. The off-gas is simply diluted and exhausted to a chimney through a fan. These incinerators typically have low temperature (around 600° C.). Consequently, several types of wastes (plastics, metal, glass, food, biomedical waste and sharps) cannot be processed in these incinerators, requiring segregation and the operation of several types of specialized equipment.
Plastic waste is processed in a plastic waste processor (PWP) that melts plastics at relatively low temperature into solid pucks. The PWPs are known to have a low processing rate and, since they are not equipped with a fume treatment system, they emit smelly fumes. The plastic pucks must be stored onboard possibly for long periods, since the navy ships can be at sea for several months. This takes up valuable space, as well as causing a nuisance to the sailors, as the plastics are often contaminated with food or other putrescible matter, releasing odours.
Food waste is typically processed in pulpers that break up food waste with large amounts of water into a fine pulp. This pulp can then be discharged to sea. However, the pulping of food requires sorting of the food, because any contaminants such as plastics are not allowed to be discharged into the sea.
Metal is separated and compressed using hydraulic presses. Glass is also separated and crushed in glass crushers. The operation of these additional pieces of equipment and the time required for segregation takes up valuable time from the sailors' routine, which would be better spent for other useful duties.
Biomedical waste can be treated in autoclaves that sterilize the waste. However, these autoclaves take up valuable shipboard space and require significant amounts of steam to operate.
Newer incinerators have been developed that operate at higher temperature and that include gas treatment systems. However, because they use oil burners, these incinerators tend to be large, typically requiring several decks of space.
Incinerators also present a number of safety problems. For example, the hot ashes that must be discharged could bum the operators. Sharps from biomedical waste stay in their original form and could cut and possibly contaminate the operators with dangerous pathogens, when being discharged with the ashes.
The present invention seeks to meet these needs and other needs.